Integrate

x402 middleware

Read and write trust inside the HTTP 402 payment handshake, with zero extra round-trips.

x402 lets a server respond with 402 Payment Required and a set of payment terms; the client retries with a signed payment. Tessera hooks into that exact moment to enforce trust and record outcomes.

Express example

typescript

import express from "express";
import { x402 } from "x402-express";
import { tesseraGuard } from "@tessera/x402";

const app = express();

app.use(
  "/api",
  // require payment AND a minimum trust score
  x402({ price: "$0.01", network: "solana" }),
  tesseraGuard({ minScore: 800, minStake: 100 }),
);

app.get("/api/forecast", (req, res) => {
  res.json({ data: "..." });
});

tesseraGuardreads the caller’s score from cache in sub-millisecond time and auto-emits an attestation when the response succeeds.

Client side

typescript

import { withX402 } from "x402-fetch";
import { attachIdentity } from "@tessera/x402";

const fetchPaid = attachIdentity(withX402(fetch), agentSigner);

// identity + payment are negotiated automatically
const res = await fetchPaid("https://api.example.com/api/forecast");

What gets recorded

The settled amount and counterparties.
A hash of the x402 receipt, anchored via state compression.
The outcome, which both sides can later dispute with evidence.

Standards alignment

The guard also speaks Google AP2 authorization objects and maps agent identities onto ERC-8004, so trust travels across ecosystems rather than locking you in.

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TypeScript SDK

MCP server